Best method to determine position at night to check for anchor drag?

[dunedin]

My advice to the OP......if this is your first night at anchor follow all the good practice here, but chose a forecast with a sensible wind strength, no more than a force 4 absolute max. My own experience of anchor alarms is they just generate a lot of stress........the time to learn to use one is once you have experience of anchoring and transits. I've tried to use one a few times and invariably switch them off. Is the only way to use one to start it just as the anchor hits the sea bed? Bit tricky at the bow as I lay out the chain.

Good point about choosing weather and not over relying on technology.

But Re anchor alarms, the one on our Raymarine plotter is rubbish, for the reason you give - just a range from a fixed point.

BUT use something better like Anchor on a tablet and massively better. Can set up any time after dropping anchor, even a day or so later, and then draw whatever shape of alarm boundary that you want. Let it run for 10 minutes or so and will see the shape of the curve as swing to the anchor. Then draw the shape you want, allowing for a bit more swing on the same trajectory.
Adjusting the shape can get it to alert you if wind changes and swings towards an obstruction or shallow, and depending on preference can get to alert if swing in opposite direction, or draw circle so doesn’t alert on tide turn unless move outside cable length.
So far had NIL false alarms, but a small number of wake ups when forecast wind shifts came through and I wanted to check things due to rock proximity (but not having dragged). Dont use when calm, settled and plenty of swing room, but certainly doesn’t cause stress but allows peaceful sleep when more windy and/or restricted.

 

[RupertW]

There's no need for full astern. It might depend on your engine but the snatch load on 10 tonnes of boat with 60hp in full astern would certainly test lots of bits of the system! Dont forget to take the load off the winch when doing this with a snubber or cleat.

I disagree with not needing full astern. Our 56HP engine gets its full revs every time we anchor and at least every couple of weeks we find a substrate that is fine on low revs but can’t hold under full. Typically shingle or a layer of sand a few inches deep over flat rock. Occasionally weeds but they pull out much earlire. If the whole system can’t cope with full astern then I won’t be sure it will cope with a 2AM squall.

 

[Supertramp]

I understand your point. My approach is to ensure a well set anchor which will take wind, full astern etc in its stride subject to the holding ability of the bottom. An anchor will set without extreme loads. Your approach adds the confidence of checking the hold. I would add this check if expecting a gale (to aid sleep!).

Returning to the OP, with 6m of chain and the rest rope, he might risk lifting the anchor out in deep water, strong winds or engine. I guess better to know than to hope.

 

[Daydream believer]

My favorite way to anchor is to go slowly ahead drop the hook so it pays out under the hull. When you've let enough out, snub it and the boat spins round as the anchor digs in. Job done, Hang anchor ball, open beer, put kettle on, mix G&T, to your preferrence.
NB: This technique only works if you have a reasonable bow overhang and don't go too fast!

You forgot the bit where it goes round the saildrive & hooks the prop.

Neither have you mentioned ( although nobody else has either) the rope to the head of the anchor with a small buoy attached so one can break it free.

I do not have an anchor winch ( No need for one actually) & I struggled to get the anchor up when I had to do it once. So the next time, I fixed a rope to the step on the CQR ( the one that is used to help one climb aboard when bows on at a pontoon) & I pulled in as much anchor rode as I could. I have a rope & a bit of chain to save weight. Then I took that extra rope ( whatever it is called) over the bow roller to the genoa winch & pulled the anchor free & up to the bow. I then motored clear ( in reverse) & when in deep water gathered the loop of rode in & then secured the anchor.
Such a faff, if it had not been for the impellor failing I would never have anchored in the first place. But needs must.

 

[Alex_Blackwood]

Master to Cadet :

'Full reverse'

Cadet to Master :

'Pardon ????'

Master to Cadet :

'Full astern !!'

Cadet to Master :

'Full astern'

KERCHING ......

Or Master to cadet who is on the wheel. "How's your head" Fine Sir, was a bit sore this morning"
Mine certainly hurt as I reacted whilst under the steering console fixing the Auto pilot!

 

[DangerousPirate]

Seeing the horrid conditions and the fact that my mate said "Awww hells to the no! I turn back" made me leave anchoring overnight for another day. Sitting in the marina with the heater on, some choccie and wait for my shoes to dry so I can take a shower

But this thread is a treasure

 

[Refueler]

Never heard of 'em. I learned this method from a genuine old salt long before such things were heard of. And I've used it too. It works. Just don't try it in a bumpy anchorage.

PBO had a guy years ago who used to create slim notebooks which had so many DIY solutions for so many aspects of boating ... it was true Practical Boating ...... I had the full set - but they got lost when I left UK.

 

[Refueler]

What a terrible idea! Limited to no swell conditions, assumes lead line doesn’t get caught on dragging anchor rode.

Oh yea of little faith .... it DID work .... but of course no good setting it in rough conditions.

 

[Poignard]

PBO had a guy years ago who used to create slim notebooks which had so many DIY solutions for so many aspects of boating ... it was true Practical Boating ...... I had the full set - but they got lost when I left UK.

John Goode wrote them and Dick Everitt illustrated them. Q

 

[michael_w]

You forgot the bit where it goes round the saildrive & hooks the prop.

Neither have you mentioned ( although nobody else has either) the rope to the head of the anchor with a small buoy attached so one can break it free.

I do not have an anchor winch ( No need for one actually) & I struggled to get the anchor up when I had to do it once. So the next time, I fixed a rope to the step on the CQR ( the one that is used to help one climb aboard when bows on at a pontoon) & I pulled in as much anchor rode as I could. I have a rope & a bit of chain to save weight. Then I took that extra rope ( whatever it is called) over the bow roller to the genoa winch & pulled the anchor free & up to the bow. I then motored clear ( in reverse) & when in deep water gathered the loop of rode in & then secured the anchor.
Such a faff, if it had not been for the impellor failing I would never have anchored in the first place. But needs must.

 

[doug748]

My favorite way to anchor is to go slowly ahead drop the hook so it pays out under the hull. When you've let enough out, snub it and the boat spins round as the anchor digs in. Job done, Hang anchor ball, open beer, put kettle on, mix G&T, to your preferrence.
NB: This technique only works if you have a reasonable bow overhang and don't go too fast!

Yes, as you no doubt know, it also works very well under sail.

.

 

[Serin]

Oh yea of little faith .... it DID work .... but of course no good setting it in rough conditions.

Thank you, sir. Of course it worked, as those of us who predate all the apps, alarms, digital wizardry etc. know. And I would rather be woken up unnecessarily by some heyho rumbelow in the galley area than drift away to my doom. But it's also good for a little gentle ribbing. The provocation of incredulous horror is guaranteed.

And to Mr. Runhardaground - you, sir, are also one in a thousand - a scholar and a gentleman. Most would just double down. I don't know where you sail, but if it's eastish, well, you would also be one in a thousand if you never did run hard aground. Just best not to do it in Brittany or some such place - somehere with fangs. Happy sailing!

 

[DangerousPirate]

Yes, as you no doubt know, it also works very well under sail.

.

Yes, as you no doubt know, it also works very well under sail.

.

This is some serious Captain Ron stuff. Sounds cool, but inaccurate and also sounds like things break easily that way

 

[FairweatherDave]

All the encouragement here to have another go with an anchor drag alarm worked and I installed Anchor Pro. The fact that you can set it up at your leisure after anchoring with a means to set a distance and bearing to the anchor made it a doddle. Tried it out on Saturday night - still checked transits as the tide turned but knew what to expect to see out the window from the plot. Great having a phone in bed with you and keeping warm. I have faith in my anchor anyway but £4.99 seemed a no brainer to my wife who is the wakeful worrier . So thanks for the encouragement folks!